Fastening strap



March 1966 J. M. ANDERSON FASTENING STRAP Filed Sept. 25, 1964 INVENTOR JOHN M fiNDf/FfO/V MW, Mink Lida ATTORNEYS United States Patent Filed Sept. 23, 1964, Ser. No. 398,572 8 Claims. (Cl. 248-71) This invention relates to an imp-rovedfastening strap or staple. i I

The fastening strap of the present invention is adapted particularly for fastening non-metallic sheathed. electrical cable to a cable support, although it may be used for any comparable fastening purpose.

An important feature of the fastening strap of the present invention is the fabrication of the nailways of plastic material incorporating an integral friction packing which tends to hold the nails in set position. Accordingly, there is no danger that the nails will fall out of the nailways in the course of manipulating the strap about a cable.

In preferred embodiments of the invention, the plastic nailways are molded with a thin plastic web spanning thereacross. Where the nails are assembled with the strap, the web is pierced by the sharp point of a nail. The web material will tear and fray out as the nail is pressed through the nailway and will yield or bend axially and form the torn web margins into a Chevron type packing about the nail with the points of the Chevrons facing in the direction of forward movement of the nail. The Chevron packing will strongly resist withdrawal of the nail, but will permit continued forward nail movement as the nail is driven into .a typical wooden support member against which the cable is placed.

Other objects, features and advantages of the present invention will appear from the following disclosure in which:

FIGURE 1 is a perspective view of a fastening strap embodying the present invention.

FIGURE 2 is an enlarged longitudinal section taken through a fastening strap embodying the present invention.

FIGURE 3 is an enlarged cross section taken through one of the nailways of a fastening strap embodying the present invention.

FIGURE 4 is a plan view of a cable strap embodying the present invention.-

Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structure. The scope of the invention is defined in the claims appended hereto.

The cable strap 9 is desirably made entirely of plastic which is molded into the configuration shown in the drawings. The strap is U-shaped in side elevation and has a bridge portion 10 with downwardly extending legs 11. The bridge 10 and legs 11 embrace a cable or comparable object to be fastened.

Integrally molded with the legs 11 are axially elongated ears 12 in each of which coaxial bores 13, 14 are molded to provide nailways for nails 15. Bore 13 has a counterbore at 21 to facilitate entry of the nail into the nailway. As best shown in FIGURE 2, the respective nailways are initially spanned midway of their overall length by a thin web 16 of the same plastic material out of which the remaining parts of the strap are molded. This is accomplished in the dies in which the strap is molded. Web 16 may typically have a thickness in the range of .003 to .005 inch.

The bores 13, 14 are desirably tapered somewhat toward their intersection of the web. The bore 13 at its "ice I narrowest adjacent web 16 has the same diameter as the nail 15. Bore 14 at its narrowest adjacent web 16 has a slightly greater diameter than nail 15, to leave space within which the torn margins of the web 16 are received when the bail is forced therethrough.

When nail 15 is inserted into bore 13 of its nailway, its sharp point 17 will pierce the center of the web 16. Continued pressure on the nail will tear and fray out and bend marginal portions 18 of the web 16 downwardly as shown in FIGURES 2 and 3 to form these portions 18 of the web into a Chevron shaped packing pointed in the direction of forward movement of the nail. Packing 18 maintains a relatively tight frictional grip on the nail to prevent the nail from falling out of the nailway during manipulating of the strap in the course of applying it to a cable or the like.

The fact that the diameter of bore 14 adjacent web 16 is larger than the diameter of the nail 15 leaves room into which the Chevron shaped web fragments 18 are accommodated as the nail is forced through the Web.

The Chevron shaped packing 18 characteristically offers much less resistance to continued forward movement of the nail than to withdrawal movement of the nail. Accordingly, the packing does not materially interfere with driving the nails into a wooden support or the like but does oppose movement of the nails out of the strap.

The packing 18 has inherent resiliency biasing it against the nail. Accordingly, frictional contact of the nail with the packing is not lost even with plastic shrinkage or thermal dimensional changes. It was found in experimenting with plastic nailways lacking the web 16 and packing Chevrons 18 that it was diflicult to maintain optimum frictional control between the nail and plastic wall of the nailway, on account of plastic shrinkage, etc.

The tapers of the bores 13, 14 toward the web 16 leaves the nail 15 free of contact with the plastic nailway except adjacent web 16 where the nail is embraced by the packing 18. This affords better control of the amount of friction on the nail. The tapers also permit limited angular adjustment of the nail 15 in its nailway. In the disclosed embodiment, the side walls of bore 13 taper at about 2 with the bore axis, and the side walls of bore 14 taper at about 14 with the bore axis.

I claim:

1. A fastening staple comprising a bridge and elongated terminal nailways formed of plastic, a nail in each nailway, said nailways integrally provided at a point spaced axially from the ends thereof with inwardly projecting plastic packing to frictionally restrain the nails therein, said packing projecting axially in the driving di rection of the nails and constituting Chevron shaped packing restraining withdrawal movement of the nails.

2. The fastening strap of claim 1 in which said nailways comprise axially aligned bores at opposite sides of the packing, the bore at the side of the packing toward which the packing projects axially having a cross section larger than the nail to accommodate the packing about the nail.

3. A fastening staple comprising a bridge and a terminal nailway formed of plastic, said nailway being axially elongated and being spanned intermediate its length by a web of pierceable and bendable plastic integral with the nailway, a nail positioned in said nailway, said web being pierced by the nail and deformed by passage of the nail therethrough into a Chevron shaped packing which frictionally grips the nail.

4. The fastening strap of claim 3 in which said nailway comprises axially aligned bores at opposite sides of the web, the bore at the side of the web toward which the web is deformed having a cross section larger than the nail to accommodate the Chevron shaped packing about the nail.

5. The fastening strap of claim 3 in which said nail- Way comprises axially aligned bores at opposite sides of the web, said bores being tapered toward said web.

6. A fastening staple comprising a bridge and an elongated terminal nailway formed of plastic, said nailway having coaxial bores leading from opposite ends of the nailway and which intersect Within the nailway intermediate its length, a nail in the nailway, said bores being tapered toward their intersection to be free of contact with the nail except at said intersection.

7. The fastening strap of claim 6 in which the intersection of the coaxial bores is initially spanned by a web integral with the plastic nailway and which is pierced by passage of the nailtherethrough to form Web fragments which constitute a packing about the nail adjacent said intersection.

8. The fastening strap of claim 7 in which one of said bores has a diameter adjacent said web greater than the nail to leave room for receiving said packing.

References Cited by the Examiner UNITED STATES PATENTS 1,218,181 3/1917 Homer 174-5 2,570,957 10/1951 Lee 248-71 2,901,200 8/1959 Voeks 24874 2,937,834 5/1960 Orenick et a1. 248-71 2,961,210 11/1960 Pfaff et a1. 25874 3,085,129 4/1963 Anderson 24874 X FOREIGN PATENTS 1,077,284 1/ 1954 Germany.

365,829 1/1932 Great Britain.

CLAUDE A. LE ROY, Primary Examiner. 

1. A FASTENING STAPLE COMPRISING A BRIDGE AND ELONGATED TERMINAL NAILWAYS FORMED OF PLASTIC, A NAIL IN EACH NAILWAY, SAID NAILWAYS INTEGRALLY PROVIDED AT A POINT SPACED AXAIALLY FROM THE ENDS THEREOF WITH INWARDLY PROJECTING PLASTIC PACKING TO FRICTIONALLY RESTRAIN THE NAILS THEREIN, SAID PACKING PROJECTING AXIALLY IN THE DRIVING DIRECTION OF THE NAILS AND CONSTITUTING CHERVON SHAPED PACKING RESTRAINING WITHDRAWAL MOVEMENT OF THE NAILS. 